The present invention relates to the field of orthodontics and, more particularly, to the construction of magnetic force orthodontic appliances and to a kit therefor.
In U.S. Pat. No. 3,353,271, of Abraham Blechman, entitled "Magnetic Orthodontic Appliance" there is described an orthodontic appliance through which corrective traction is applied to teeth by magnetically generated force derived from permanent magnets mounted intraorally by arch wires and anchoring bands on the buccal sides of the teeth, the spacing between the magnets being adjusted to regulate the traction force produced. Three embodiments of magnets are described in the patent, the first is right rectangular prismatic of "Alnico", approximately 6 mm.times.4 mm.times.3 mm, and provided with a "Russel" lock at its small end to suspend it from a base arch wire. The magnetic polarization is across the 4 mm dimension between the 3 mm.times.6 mm faces. The second embodiment replaces the "Russel" lock with a groove for the arch wire and a set-screw to secure the element to the wire. Finally, the third embodiment has a right circular cylindrical magnet body with a buccal tube attached to one of the circular ends of the body.
While the Blechman patented appliance represented a significant advance in the art at the time, the magnets were bulky and provided limited versatility in construction of appliances from patient to patient.
In U.S. Pat. No. 4,424,030, of Harry Smiley and Abraham Blechman, entitled "Integrated Oral Magnetic Osteogenic and Orthodontic Appliances" there is described, inter alia, a magnetic module consisting of a permanent magnet anchored in a sleeve of surgical grade stainless steel by a bio-compatible adhesive material, such as an acrylic, epoxy, urethane, or other suitable material. The patent states that the exposed poles of the magnet are preferably coated with the adhesive material to prevent corrosion products from leaching into the oral cavity when SmCo or AlNiCo magnets are used. Mounting of the module is obtained in one embodiment by soldering to the lingual aspect of the module sleeve a rectangular orthodontic tube for mounting on 0.022".times.0.028" arch wire.
Again, attaching conventional orthodontic tubes to the magnetic module produced a bulky component. Moreover, it has been discovered that the use of conventional arch wire for mounting the modules does not provide in a simple and convenient manner adequate rigidity to firmly mount a module in an appliance. Positive mounting of each module is necessary if predictable forces are to be obtained. Also, it was found that the single edgewise wire had a tendency to break.
Therefore, an object of the present invention is to provide magnetic modules, as part of an overall system for creating fixed appliances within the oral cavity, which modules are of significantly smaller size than those disclosed in said patents.
Another object is to provide such magnetic modules of smaller size without sacrifice of available traction forces.
A further object is to provide magnetic modules for construction of orthodontic fixed appliances, which modules are constructed in a manner that facilitates appliance construction and custom tailoring to the individual patient.
Yet another object is to provide magnetic modules that can be installed either buccally or lingually or both depending upon the desired orthodontic procedure, all without undue patient discomfort.
It is a further object of the invention to provide from commonly available orthodontic edgewise wire an attachment wire of increased strength and utility especially suited to mounting magnetic modules as comtemplated herein.